Air heater



Oct. 23, 1928.

H. F. GAUSS AIR HEATER Filed Jan. 14, 1926 ATTORNA'YS.

Patented 0a. 23, 1928.

UNITED STATES PATENT OFFICE.

HENRY I. GAUSS, OF MOSCOW, IDAHO, ASSIGNOR TO HEINE BOILER COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

AIR HEATER.

Application filed January 14, 1926 Serial No. 81,335..

This invention relates to heating devices of the kind that are used for causing one gaseous medium to be heated by another gaseous medium of a higher temperature, and particularly recuperative air heaters of the tubular type that are used for heating air which is supplied to the furnace of a boiler or other heating apparatus to support combustion.

Ono object of my invention is to provide an air heater of the general type mentioned, that is particularly efiicient, due to the fact that the parts of same which constitute passageways for the air that is to be heated and the gases which are used to heat said air, are so constructed and aranged that the gases and the air will flow through the heater in direct contact with the elements that absorb heat from the gases and transmit said heat to theair.

Another object is to provide an eflicient air heater that is inexpensive to construct.

Figure 1 of the drawings is a side elevational view of an air heater embodying my invention, combined with a water tube boiler.

Figure 2 is a vertical longitudinal sectional view of said air heater; and

Figure 3 is a front elevational View of said heater.

Referring to the drawings, which illustrate the preferred form of my invention, A c esignates a boiler or other heating apparatus, B designates a heater that is arranged in the path of gases which escape from said boiler. C designates a fan or other suitable suction device for drawing said gases through the heater B, and D designates a fan or other suitable device that is used for drawing air through the heater B and thereafter causing said air to be supplied to the furnace of the boiler A to support combustion. The heater B is a recuperative heater of the tubular type and is preferably composed of a sheet metal casing constructed so as to form a vertical gas passageway through whichthe escaping gases from the boiler circulate, as indicated by the arrows w in Figure 2, and an air passageway 1 through which air circulates in a tortuous path, as indicated by the arrows y in Figure 2. Tubular elements are combined with said passageways so as to absorb heat from the escaping gases and transmit said heat to the air that is being supplied to the boiler to support combustion, and while the particular arrangement and location of said tubular elements may be changedin various ways Without departing from the spirit of my invention, I prefer to arrange some of said tubular ele ments in the gas passageway in such a manner that the gases will circulate over the exterior of said elements and the air will circulate through said elements, and arrange some of: said tubular elements in the air passageway in such a manner that the air will circulate'over the ex erior of said elements and the gases will circulate through said elements. One convenient way of constructing the air heater B is to provide the casing of same with a tubular gas intake portion 2 and a discharge portion 3 of any preferred cross-sectional shape, that are connected together by a bank of verticallydisposed tubes 4 whose lower ends are expanded into or connected in any other suitable way to a tube sheet at the upper end of the intake portion 2 and whose upper ends are expanded into or connected in any other suitable way toa tube sheet at the lower end of the discharge portion 3, the heater being so arranged that the escaping gases will flow upwardly through the intake portion 2, thence through the tubes 4 and thence upwardly through the gas discharge portion 3 of the casing. The air passageway of the heater is formed by a substantially S-shaped portion 1 of the casing, a top bank of horizontallydisposed tubes 5 arranged transversely of the gas discharge portion 3 of the casing and communicating with the upper end of said S-shaped portion 1 and a bottom bank of horizontally-disposed tubes 6 arranged transversely of the gas intake portion 2 of the easing and communicating with the lower end of said S-shaped portion. The middle bank of vertical tubes 4 through which the gases flow in traveling from the intake portion 2 to the discharge portion 3 of the gas passageway are located in the horizontal portion or intermediate. part of the S-shaped portion 1 of the casing.

lVhen the boiler is in operation the escaping gases circulate over the exterior of the botom bank of tubes 6, thence through the Vertical tubes 4 and thence over the exterior of the top bank of tubes 5, said horizontal banks of tubes 6 and 5 virtually acting as bafiies that effectively break up and mix the gasesandinsuresaidgasescirculatingthrough the heater in direct contact with the elements that are used to abstract heat from said gases. Likewise, the bank of Vertical tubes l in the air passageway virtually act battles that mix the air, and thus insure the air circulating through the heater in direct contact with the elements that transmit heat to said air from the escaping gases. WVhile I prefer to arrange the tubular elements of the heater in such a manner that the medium which circulates through the interior of said elements flows at substantially right angles to the medium that circulates over the exterior of said elements, thereby insuring a high rate of heat transfer, this particular arrangement is not essential to the successful operation of my improved heater. In addi tion to being exceptionally eficient, an air heater of the construction above described is compact and inexpensive to manufacture.

Having thus described my invention, what I claim as new and desire to secure bg Letters Patent is:

1. An air heater, comprising a casing provided with a gas intake portion and a gas discharge portion, a bank of tubes'that connect said intake and discharge portions together, open-ended tubes arranged transversely of said intake and discharge portions and ad apted to serve as conduits through which air circulates, and an air passageway in the casing communicting with said air conduits and arranged so as-to encase' the tubes that join the gas intake and the gas discharge portions of the casing together. i

2. A. device for heating one gaseous medium by another gaseous medium of a higher temperature, comprising a casing provided with an intake portion and a discharge portion, a bank of tubes which joins said portions together, other banks of tubes arranged transversely of said intake and discharge portions and disposed at substantially right angles tothe tubes that join said por ions together, and a passageway in the casing that establishes communication between the tubes in said intake and discharge portions and which encloses the tubes that join said intake and dis charge portions together.

3. An air heater, comprising a casing provided with a gas intake portion and a gas dis-' charge portion, a bank of gas tubes that join said portions together, a substantially S shaped passageway in the casing disposed so that said gas tubes extend transversely across the intermediate part of same, a bank of air tubes arranged transversely of the gas intake portion of the casing and communicating at one end with said air passageway, and a separate bank of tubes arranged transversely of the gas discharge portion 01 said casing and communicating with the opposite end of said air passageway.

HENRY F. GAUSS. 

